class Solution:
    def isBalanced(self, root: TreeNode) -> bool:
        if self.get_height(root) != -1:
            return True
        else:
            return False

    def get_height(self, root: TreeNode) -> int:
        # Base Case
        if not root:
            return 0
        # 左
        if (left_height := self.get_height(root.left)) == -1:
            return -1
        # 右
        if (right_height := self.get_height(root.right)) == -1:
            return -1
        # 中
        if abs(left_height - right_height) > 1:
            return -1
        else:
            return 1 + max(left_height, right_height)
